Our previous study of Latino children's exposure to environmental tobacco smoke (ETS) revealed a serendipitous finding. An unusually high proportion of Latino parents showed great interest in the results of analysis of their children's hair to measure ETS exposure, interest that had not been encountered in previous cancer prevention studies that included other types of biological measures. Parents frequently asked for feedback during the course of the study, but because the hair analysis was a measurement tool and not part of the intervention, results of hair analysis had to be withheld until the end of the study. At that time, the present investigators grappled with the question of the best way to present individual children's hair analysis to the parent so as to maximize understandability and usefulness In addition, the unusual interest on the part of parents in their children's hair analysis suggested that feedback could potentially be a powerful ETS reduction intervention. Based on this previous work, the proposed pilot research will use a one-group, pre-post design with 60 Latino parent-child pairs to accomplish two primary goals. The first is to explore the usability of hair nicotine feedback for a future intervention trial to modify parents' behavior related to children's ETS exposure. Three feedback versions will be presented in a counterbalanced fashion to control for presentation order effects. Usability/preference measures will include parents' liking of the feedback in various formats and mode of delivery, and perceptions of the usefulness of the feedback for changing behavior. Second, the research will examine the impact of hair nicotine feedback and related counseling on changes in Latino parents' behavior related to their children's ETS exposure Intervention efforts, directed toward a smoking parent (e.g., the mother), will include a home visit to provide nicotine feedback and counseling, two mailers presenting alternative versions of the feedback, and a supportive telephone call delivered over a 6-week period A trained community health advisor, or promotora, will provide the feedback and support for behavior change using a culturally relevant approach. Assessments conducted by a bicultural measurement technician will collect usability measures, parent-reports of children's ETS exposure, and children's hair nicotine to assess feedback format preference and intervention impact.